In the last entry we had mean and standard variation data for five different conditions. Now let us assume that we have only two different conditions, but have measured with three different instruments A, B and C. We have used a ANOVA to verify that the data for the two conditions are significant different. As a result the plot in Fig. 1 should be created.

Now every instrument is stored in a different data block containing both conditions as columns.

The color definitions and axes settings are done in a similar way as in the previous blog entry. Note that we have to define two more colors for the boxes, because we use three different colors. Also we define a black line to plot the significance indicator (arrow).

For the plot the index command is used to plot first condition A, then B and then C by using block 0,1, and 2 respectively. The x-position of the boxes for instrument A are slightly shifted to the left, the ones for C to the right by subtracting or adding the value of bs. The value of bs has the width of one box in order to plot the boxes side by side.

Then I would modify the plotting command a little bit, that not only a forth box is plotted, but also the boxes are centered again around the condition tics and are made a little bit narrower. The result is shown in Fig. 2.

Hi Daniela.
The easiest solution is to use the pdfcairo terminal. The only thing you have to do, is to change the size to cm or inches, because pixel is not supported at the moment. Change the terminal settings to these two lines in the code from Fig.1 and just plot it.